Síntesis de 1-fenil-2-propanona (P2P) a partir de dietil(fenilacetil)malonato
- Thread starter G.Patton
- Start date
¿Se refiere a la destilación simple en lugar de la de vacío? Puede, 216 grados C es el punto de ebullición en condiciones normales.
Chicos, no caigáis en el culto al santo reflujo. El reflujo no tiene valor en sí mismo, salvo por la ilusión de que algo ocurre que crea.
Con H2SO4 y ácido oxálico (mejor), pero el ácido fosfórico y casi cualquier ácido orgánico como el acético o fórmico o cítrico trabajo se obtiene junto a los rendimientos cuantitativos si se calienta la mezcla lentamente durante dos horas a no más de 95 ° C, mantiene allí durante 30 minutos y luego dejar que se enfríe. Añada una pequeña cantidad de disolvente que no sea DCM (tolueno, xileno, éter), ya que el ácido orgánico puede desprenderse, por lo que se recomienda recogerlo desde la parte superior. Se puede utilizar éter de petróleo 40/60 y no se necesita mucho, pero al final se obtienen TRES capas: La capa superior es Pet-Ether con P2P disuelto. La capa intermedia es P2P con Pet-Ether disuelto*. Y abajo está la mezcla ácida (que se puede reutilizar sin problemas).
*Suena raro pero es así: Ambos, Pet-Ether y P2P disuelven algo del otro pero no son libremente miscibles. Y así se obtiene las tres capas que me llevó al lado de los frutos secos ya hace mucho tiempo. Hasta que me di cuenta de esto.......
200 g de ácido oxálico dihidratado
300 ml de agua
100 ml H2SO4 37% (ácido de batería)
no todo el ácido oxálico se disuelve - no hay problema
Con esto se puede procesar un mínimo de 200 ml 20230 aceite rojo
Es necesario agitar muy fuerte todo el tiempo.
La mezcla de agua y ácido puede reutilizarse.
No más de 95 °C da P2P amarillo claro directamente sin vapor u otra destilación.
Cuando se usa un sep-funnel es mejor separar mientras este caliente y el oxalico no se caiga.o se pone en un vaso de precipitados en el congelador con el fondo del vaso tocando el frio para que empiece a cristalizar desde alli. Si haces esto no necesitas disolvente en absoluto, el ácido y el agua cristalizando desde el fondo llevarán el P2P a la parte superior y puedes verterlo después de dos o tres horas y NO quedará P2P.
Hice un montón de trabajo en este caso, lol
Con H2SO4 y ácido oxálico (mejor), pero el ácido fosfórico y casi cualquier ácido orgánico como el acético o fórmico o cítrico trabajo se obtiene junto a los rendimientos cuantitativos si se calienta la mezcla lentamente durante dos horas a no más de 95 ° C, mantiene allí durante 30 minutos y luego dejar que se enfríe. Añada una pequeña cantidad de disolvente que no sea DCM (tolueno, xileno, éter), ya que el ácido orgánico puede desprenderse, por lo que se recomienda recogerlo desde la parte superior. Se puede utilizar éter de petróleo 40/60 y no se necesita mucho, pero al final se obtienen TRES capas: La capa superior es Pet-Ether con P2P disuelto. La capa intermedia es P2P con Pet-Ether disuelto*. Y abajo está la mezcla ácida (que se puede reutilizar sin problemas).
*Suena raro pero es así: Ambos, Pet-Ether y P2P disuelven algo del otro pero no son libremente miscibles. Y así se obtiene las tres capas que me llevó al lado de los frutos secos ya hace mucho tiempo. Hasta que me di cuenta de esto.......
200 g de ácido oxálico dihidratado
300 ml de agua
100 ml H2SO4 37% (ácido de batería)
no todo el ácido oxálico se disuelve - no hay problema
Con esto se puede procesar un mínimo de 200 ml 20230 aceite rojo
Es necesario agitar muy fuerte todo el tiempo.
La mezcla de agua y ácido puede reutilizarse.
No más de 95 °C da P2P amarillo claro directamente sin vapor u otra destilación.
Cuando se usa un sep-funnel es mejor separar mientras este caliente y el oxalico no se caiga.o se pone en un vaso de precipitados en el congelador con el fondo del vaso tocando el frio para que empiece a cristalizar desde alli. Si haces esto no necesitas disolvente en absoluto, el ácido y el agua cristalizando desde el fondo llevarán el P2P a la parte superior y puedes verterlo después de dos o tres horas y NO quedará P2P.
Hice un montón de trabajo en este caso, lol
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- By w2x3f5
indique el rendimiento de la sustancia p2p por favor.
¿tiene aceite rojo? extrañamente, yo tenía aceite amarillo con el mismo número.
¿tiene aceite rojo? extrañamente, yo tenía aceite amarillo con el mismo número.
Is there any other way to isolate the phenylacetic acid besides putting it in the refrigerator? Will not separating affect my future work?
- By William D.
You can crystallize this in a cool place and filter after. In another case, you can distill the fractions. For the following steps, you cannot leave PPA.
I would like to know if this synthesis is also working with phosphoric acid ( h3pO4) I appreciate your work and time
And what would be the amount ( phosphoric acid 85%)
Currently performing a test on the substrate with 75% phosphoric acid. No exact amounts used.
Trying with about 1:2 (Precursor to Phosphoric acid), again no exact amounts used but will report back if it works at all.
Trying with about 1:2 (Precursor to Phosphoric acid), again no exact amounts used but will report back if it works at all.
Tests using 75% phosphoric acid 1:2 (substrate to acid). 1 hour and 30 minutes into the reaction. Took a small "sniff test" and I seem to be able to detect the distinct odour of phenyl-2-propanone.
Lots of bubbling in the reaction that started as early as 60 degress celcius.
Again no exact amounts was actually used as the substrate I tried was a sample purchase from a chinese vendor (not on this site). Red liquid just like the photos of the malonate everywhere, the smell was not super pleasant but not horrible. Around 100 euro per kilo (actually less considering shipping was included)
Lots of bubbling in the reaction that started as early as 60 degress celcius.
Again no exact amounts was actually used as the substrate I tried was a sample purchase from a chinese vendor (not on this site). Red liquid just like the photos of the malonate everywhere, the smell was not super pleasant but not horrible. Around 100 euro per kilo (actually less considering shipping was included)
2 hours and 23 minutes into the reaction and I can confirm 100% that 75% phosphoric acid definitely works. However the reaction is still bubbling from CO2 evolution, so the reaction is not done.
The smell of phenyl-2-propanone is now too strong to dispute. The substrate was legit.
Further experimentation needs to be done to determine optimal amount of phosphoric acid.
Previous experience: [P2NP (from benzaldehyde & nitroethane) to phenyl-2-propanone with iron powder and HCL] and [MAPA to phenyl-2-propanone with hydrochloric acid])
If I remember correctly the p2np to phenyl-2-propanone with iron powder and HCL sometimes produced phenyl-2-propanone with an acrid smell. however the smell of the phenyl-2-propanone from the malonate is extremely sweet and that of pure phenyl-2-propanone.
Will store the resulting phenyl-2-propanone as a powder by reacting it with metabisulfite.
edit: Also beware of alibaba sellers of BMK precursors, one of them was not legit. (check the bot reviews, the fake sellers strictly sell precursors and have fake reviews of GBL and synthetic cannabinoid indole derivatives)
The smell of phenyl-2-propanone is now too strong to dispute. The substrate was legit.
Further experimentation needs to be done to determine optimal amount of phosphoric acid.
Previous experience: [P2NP (from benzaldehyde & nitroethane) to phenyl-2-propanone with iron powder and HCL] and [MAPA to phenyl-2-propanone with hydrochloric acid])
If I remember correctly the p2np to phenyl-2-propanone with iron powder and HCL sometimes produced phenyl-2-propanone with an acrid smell. however the smell of the phenyl-2-propanone from the malonate is extremely sweet and that of pure phenyl-2-propanone.
Will store the resulting phenyl-2-propanone as a powder by reacting it with metabisulfite.
edit: Also beware of alibaba sellers of BMK precursors, one of them was not legit. (check the bot reviews, the fake sellers strictly sell precursors and have fake reviews of GBL and synthetic cannabinoid indole derivatives)
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Appreciate your work hope we can get a detailed syntheses of phosphoric acid. I have 85% of phosphoric acid and hope to find a way that is working
Take notice: Ignore the 5 hour bullshit, it was not enough for me with 75% phosphoric acid. I ended up with way too much oil than theoretically possible. i.e. it was a mixture of the precursor and product, the precursor had not fully reacted. (I also detected the precursor smell when working up the reaction). This is a big problem according to me as they are annoying to separate from eachother. Therefor it is important, imo, to run the reaction to completion, I'd rather have bi-products or some slight polymerisation from running the reaction longer than unreacted precursor.
Better to end the reaction when it no longer is bubbling or bubbling very little.
Also don't wait for a detailed guide. Just try it yourself using small amounts.
Either use a 1:1 or 1:2 ratio of precursor to phosphoric acid. This is not that complex.
Better to end the reaction when it no longer is bubbling or bubbling very little.
Also don't wait for a detailed guide. Just try it yourself using small amounts.
Either use a 1:1 or 1:2 ratio of precursor to phosphoric acid. This is not that complex.
May I ask which solvent can be used instead of ether?
Use any compatible solvent, Such as DCM, MTBE etc etc.
The solvent needs to follow 2 criteria,
* Should not be too easy to hydrolyse (e.g. ethyl acetate hydrolyses in basic conditions, so if used you have to minimize it by either low % NaOH solution or be fast)
* Needs to be non polar and not misicible/soluble in water.
Preferably low boiling point so it can be removed easy later, but if that is not a concern for you
you also got things like toluene
I currently use an ether but not diethyl.
The solvent needs to follow 2 criteria,
* Should not be too easy to hydrolyse (e.g. ethyl acetate hydrolyses in basic conditions, so if used you have to minimize it by either low % NaOH solution or be fast)
* Needs to be non polar and not misicible/soluble in water.
Preferably low boiling point so it can be removed easy later, but if that is not a concern for you
you also got things like toluene
I currently use an ether but not diethyl.
↑View previous replies…
May I ask if I can still succeed by adding 20% alkaline solution after heating and refluxing, but the pH value can only reach 7?
Sorry you have to be clearer in your writing mate.
An alkaline solution can never be below 7, alkaline is just chemistry speech for "basic" (i.e. above 7 on the pH scale)
Why is it important for you too not go below 7? (or above 7)?
Please tell me which reaction and chemicals you intend or are currently using. You doing the sulfuric acid variant, phosphoric acid or saponification + hydrochloric acid variant?
An alkaline solution can never be below 7, alkaline is just chemistry speech for "basic" (i.e. above 7 on the pH scale)
Why is it important for you too not go below 7? (or above 7)?
Please tell me which reaction and chemicals you intend or are currently using. You doing the sulfuric acid variant, phosphoric acid or saponification + hydrochloric acid variant?
Heating reflux for 5 hours, adding 20% sodium hydroxide solution to the ice bath, the pH value is stuck at 7
Assume you meant you added the alkaline to the reaction mixture while it's in a ice bath. Anyway if the pH value is stuck at 7, your pH meter or pH paper doesn't work correctly. What are you using to measure the pH?
And what acid did you use?
Edit:
The first guy who replied to this thread said the following (note the pH thing with the saponification or whatever)
"Perform CAS 20320-59-6 official procedure After 4 hours of reaction at 80°C, stop heating, then adjust the alkali pH with sodium hydroxide, until 7, it can't go up, stratification appears, the oil layer is on top, and then ether extraction is added, and the stratification begins, and the ether layer is extracted, and the upper layer starts, and the distillation at atmospheric pressure at 220° keeps going up, and the temperature keeps it at 110°, and a lot of liquid is distilled, and I think it's ether, and then it starts to appear, and this phenomenon in the flask I thought it would be 216° distillation to produce P2P, but there is no problem How can I remedy it "
And what acid did you use?
Edit:
The first guy who replied to this thread said the following (note the pH thing with the saponification or whatever)
"Perform CAS 20320-59-6 official procedure After 4 hours of reaction at 80°C, stop heating, then adjust the alkali pH with sodium hydroxide, until 7, it can't go up, stratification appears, the oil layer is on top, and then ether extraction is added, and the stratification begins, and the ether layer is extracted, and the upper layer starts, and the distillation at atmospheric pressure at 220° keeps going up, and the temperature keeps it at 110°, and a lot of liquid is distilled, and I think it's ether, and then it starts to appear, and this phenomenon in the flask I thought it would be 216° distillation to produce P2P, but there is no problem How can I remedy it "
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